New Features

Generators

The :generator:Ninja generator learned to produce phony targets of the form sub/dir/all to drive the build of a subdirectory. This is equivalent to cd sub/dir; make all with :ref:Makefile Generators.
The :generator:Ninja generator now includes system header files in build dependencies to ensure correct re-builds when system packages are updated.
The :generator:Visual Studio 14 2015 generator learned to support the Clang/C2 toolsets, e.g. with the -T v140_clang_3_7 option. This feature is experimental.

Commands

The :command:add_custom_command and :command:add_custom_target commands learned how to use the :prop_tgt:CROSSCOMPILING_EMULATOR executable target property.
The :command:install command learned a new EXCLUDE_FROM_ALL option to leave installation rules out of the default installation.
The :command:list command gained a FILTER sub-command to filter list elements by regular expression.
The :command:string(TIMESTAMP) and :command:file(TIMESTAMP) commands gained support for the %s placeholder. This is the number of seconds since the UNIX Epoch.

Variables

A :variable:CMAKE_DEPENDS_IN_PROJECT_ONLY variable was introduced to tell :ref:Makefile Generators to limit dependency scanning only to files in the project source and build trees.
A new :variable:CMAKE_HOST_SOLARIS variable was introduced to indicate when CMake is running on an Oracle Solaris host.
A :variable:CMAKE_<LANG>_STANDARD_INCLUDE_DIRECTORIES variable was added for use by toolchain files to specify system include directories to be appended to all compiler command lines.
The :variable:CMAKE_<LANG>_STANDARD_LIBRARIES variable is now documented. It is intended for use by toolchain files to specify system libraries to be added to all linker command lines.
A :variable:CMAKE_NINJA_OUTPUT_PATH_PREFIX variable was introduced to tell the :generator:Ninja generator to configure the generated build.ninja file for use as a subninja.
A :variable:CMAKE_TRY_COMPILE_PLATFORM_VARIABLES variable was added for use by toolchain files to specify platform-specific variables that must be propagated by the :command:try_compile command into test projects.
A :variable:CMAKE_TRY_COMPILE_TARGET_TYPE variable was added to optionally tell the :command:try_compile command to build a static library instead of an executable. This is useful for cross-compiling toolchains that cannot link binaries without custom flags or scripts.

Properties

A :prop_tgt:DEPLOYMENT_REMOTE_DIRECTORY target property was introduced to tell the :generator:Visual Studio 9 2008 and :generator:Visual Studio 8 2005 generators to generate the "remote directory" for WinCE project deployment and debugger settings.
A :prop_tgt:<LANG>_CLANG_TIDY target property and supporting :variable:CMAKE_<LANG>_CLANG_TIDY variable were introduced to tell the :ref:Makefile Generators and the :generator:Ninja generator to run clang-tidy along with the compiler for C and CXX languages.
A :prop_test:TIMEOUT_AFTER_MATCH test property was introduced to optionally tell CTest to enforce a secondary timeout after matching certain output from a test.
A :prop_tgt:VS_CONFIGURATION_TYPE target property was introduced to specify a custom project file type for :ref:Visual Studio Generators supporting VS 2010 and above.
A :prop_dir:VS_STARTUP_PROJECT directory property was introduced to specify for :ref:Visual Studio Generators the default startup project for generated solutions (.sln files).

Modules

The :module:CMakePushCheckState module now pushes/pops/resets the variable CMAKE_EXTRA_INCLUDE_FILES used in :module:CheckTypeSize.
The :module:ExternalProject module leared the GIT_SHALLOW 1 option to perform a shallow clone of a Git repository.
The :module:ExternalProject module learned to initialize Git submodules recursively and also to initialize new submodules on updates. Use the GIT_SUBMODULES option to restrict which submodules are initialized and updated.
The :module:ExternalProject module leared the DOWNLOAD_NO_EXTRACT 1 argument to skip extracting the file that is downloaded (e.g., for self-extracting shell installers or .msi files).
The :module:ExternalProject module now uses TLS_VERIFY when fetching from git repositories.
The :module:FindBLAS and :module:FindLAPACK modules learned to support OpenBLAS <https://www.openblas.net>__.
The :module:FindCUDA module learned to find the cublas_device library.
The :module:FindGTest module gtest_add_tests function now causes CMake to automatically re-run when test sources change so that they can be re-scanned.
The :module:FindLTTngUST module was introduced to find the LTTng-UST library.
The :module:FindPkgConfig module learned to optionally create imported targets for the libraries it has found.
The :module:FindProtobuf module learned to provide a Protobuf_VERSION variable and check the version number requested in a :command:find_package call.
The :module:InstallRequiredSystemLibraries module learned a new CMAKE_INSTALL_UCRT_LIBRARIES option to enable app-local deployment of the Windows Universal CRT libraries with Visual Studio 2015.

Platforms

The Clang compiler is now supported on CYGWIN.
Support was added for the Bruce C Compiler with compiler id Bruce.

CTest

The :command:ctest_update command now looks at the :variable:CTEST_GIT_INIT_SUBMODULES variable to determine whether submodules should be updated or not before updating.
The :command:ctest_update command will now synchronize submodules on an update. Updates which add submodules or change a submodule's URL will now be pulled properly.

CPack

The :cpack_gen:CPack DEB Generator learned how to handle $ORIGIN in CMAKE_INSTALL_RPATH when :variable:CPACK_DEBIAN_PACKAGE_SHLIBDEPS is used for dependency auto detection.
The :cpack_gen:CPack DEB Generator learned how to generate DEBIAN/shlibs control file when package contains shared libraries.
The :cpack_gen:CPack DEB Generator learned how to generate DEBIAN/postinst and DEBIAN/postrm files if the package installs libraries in ldconfig-controlled locations (e.g. /lib/, /usr/lib/).
The :cpack_gen:CPack DEB Generator learned how to generate dependencies between Debian packages if multi-component setup is used and :variable:CPACK_COMPONENT_<compName>_DEPENDS variables are set. For backward compatibility this feature is disabled by default. See :variable:CPACK_DEBIAN_ENABLE_COMPONENT_DEPENDS.
The :cpack_gen:CPack DEB Generator learned how to set custom package file names including how to generate properly-named Debian packages::

<PackageName><VersionNumber>-<DebianRevisionNumber><DebianArchitecture>.deb

For backward compatibility this feature is disabled by default. See :variable:CPACK_DEBIAN_FILE_NAME and :variable:CPACK_DEBIAN_<COMPONENT>_FILE_NAME.
The :cpack_gen:CPack DEB Generator learned how to set the package release number (DebianRevisionNumber in package file name when used in combination with DEB-DEFAULT value set by :variable:CPACK_DEBIAN_FILE_NAME). See :variable:CPACK_DEBIAN_PACKAGE_RELEASE.
The :cpack_gen:CPack DEB Generator learned how to set the package architecture per-component. See :variable:CPACK_DEBIAN_<COMPONENT>_PACKAGE_ARCHITECTURE.
The :cpack_gen:CPack DragNDrop Generator learned a new option to skip the /Applications symlink. See the :variable:CPACK_DMG_DISABLE_APPLICATIONS_SYMLINK variable.
The :module:CPackIFW module gained a new :command:cpack_ifw_update_repository command to update a QtIFW-specific repository from a remote repository.
The :cpack_gen:CPack RPM Generator learned how to set RPM dist tag as part of RPM Release: tag when enabled (mandatory on some Linux distributions for e.g. on Fedora). See :variable:CPACK_RPM_PACKAGE_RELEASE_DIST.
The :cpack_gen:CPack RPM Generator learned how to set default values for owning user/group and file/directory permissions of package content. See :variable:CPACK_RPM_DEFAULT_USER, :variable:CPACK_RPM_DEFAULT_GROUP, :variable:CPACK_RPM_DEFAULT_FILE_PERMISSIONS, :variable:CPACK_RPM_DEFAULT_DIR_PERMISSIONS and their per component counterparts.
The :cpack_gen:CPack RPM Generator learned how to set user defined package file names, how to specify that rpmbuild should decide on file name format as well as handling of multiple rpm packages generated by a single user defined spec file. See :variable:CPACK_RPM_FILE_NAME and :variable:CPACK_RPM_<component>_FILE_NAME.
The :cpack_gen:CPack RPM Generator learned how to correctly handle symlinks that are pointing outside generated packages.

Other

The :manual:Compile Features <cmake-compile-features(7)> functionality is now aware of features supported by Intel C++ compilers versions 12.1 through 16.0 on UNIX platforms.

Deprecated and Removed Features

The :module:CMakeForceCompiler module and its macros are now deprecated. See module documentation for an explanation.
The :command:find_library, :command:find_path, and :command:find_file commands no longer search in installation prefixes derived from the PATH environment variable on non-Windows platforms. This behavior was added in CMake 3.3 to support Windows hosts but has proven problematic on UNIX hosts. Users that keep some <prefix>/bin directories in the PATH just for their tools do not necessarily want any supporting <prefix>/lib directories searched. One may set the CMAKE_PREFIX_PATH environment variable with a :ref:semicolon-separated list <CMake Language Lists> of prefixes that are to be searched.
The :generator:Visual Studio 7 .NET 2003 generator is now deprecated and will be removed in a future version of CMake.
The :generator:Visual Studio 7 generator (for VS .NET 2002) has been removed. It had been deprecated since CMake 3.3.
The :generator:Visual Studio 6 generator has been removed. It had been deprecated since CMake 3.3.

Other Changes

The precompiled OS X binary provided on cmake.org now requires OS X 10.7 or newer.
On Linux and FreeBSD platforms, when building CMake itself from source and not using a system-provided libcurl, OpenSSL is now used by default if it is found on the system. This enables SSL/TLS support for commands supporting network communication via https, such as :command:file(DOWNLOAD), :command:file(UPLOAD), and :command:ctest_submit.
The :manual:cmake(1) --build command-line tool now rejects multiple --target options with an error instead of silently ignoring all but the last one.
:prop_tgt:AUTOMOC now diagnoses name collisions when multiple source files in different directories use #include <moc_foo.cpp> with the same name (because the generated moc_foo.cpp files would collide).
The :module:FindBISON module bison_target() command now supports special characters by passing the VERBATIM option to internal :command:add_custom_command calls. This may break clients that added escaping manually to work around the bug.
The :module:FindFLEX module flex_target() command now supports special characters by passing the VERBATIM option to internal :command:add_custom_command calls. This may break clients that added escaping manually to work around the bug.
The :module:FindProtobuf module input and output variables were all renamed from PROTOBUF_ to Protobuf_ for consistency with other find modules. Input variables of the old case will be honored if provided, and output variables of the old case are always provided.
The :cpack_gen:CPack RPM Generator now supports upper cased component names in per component CPackRPM specific variables. E.g. component named foo now expects component specific variable to be CPACK_RPM_FOO_PACKAGE_NAME while before it expected CPACK_RPM_foo_PACKAGE_NAME. Upper cased component name part in variables is compatible with convention used for other CPack variables. For back compatibility old format of variables is still valid and preferred if both versions of variable are set, but the preferred future use is upper cased component names in variables. New variables that will be added to CPackRPM in later versions will only support upper cased component variable format.
The CPack NSIS generator's configuration file template was fixed to quote the path to the uninstaller tool used by the :variable:CPACK_NSIS_ENABLE_UNINSTALL_BEFORE_INSTALL option. This avoids depending on an insecure Windows feature to run an uninstaller tool with a space in the path.